With rapid development of the semiconductor technology and increase in definition of image data in recent years, an amount of image data to be processed by a device or a system explosively goes on increasing. Further, due to improvement in quality of display in display means such as a liquid crystal panel, a request for image processing aimed at a higher added value, and emergence of 3D-TVs, there has been made a requirement for performing processing on a vast amount of image data.
At the time of performing arithmetic processing (correction processing, etc.) on image data, in many cases, image data in processing, data calculated from the image data, and some other data need to be temporarily held in a memory. However, with increasingly high definition of image data as described above, a vast amount of data is to be handled. For this reason, a large-capacity memory is required for holding those data into the memory while leaving them raw data. However, such a large-capacity memory is high-priced, and thus brings about a rise of manufacturing cost.
For suppressing manufacturing cost of the device and the system, an amount of data to be held may be reduced so as to allow processing without mounting of the large-capacity memory. As means for this, there is formed a configuration where the data to be held is once compressed to reduce an amount of the data, and this reduced data is held. This can reduce a required capacity of the memory. This is a technique being in general use.
The method of temporarily storing previously obtained processed data in the memory and reading the processed data from this memory to execute processing on pixel data as an object is applied to a variety of scenes. For example, Patent Document 1 below discloses a method of deciding a value of a voltage to be applied to a pixel electrode in accordance with a change from immediately preceding pixel data in order to improve response characteristics of a liquid crystal display device. This has been performed for the sake of solving a problem peculiar to liquid crystal in which a response speed at the time of a transmittance changing with respect to a change in applied voltage and charging characteristics with respect to a change in permittivity of liquid crystal are poor and sufficiently responding to a quick change in image signal is difficult.
Further, Patent Document 2 below discloses a technique regarding a display device for displaying a three-dimensional (3D) video. The 3D display system has a form of alternately displaying left eye images and right eye images to realize a 3D display. In the case of forming a configuration where the left eye image is outputted over each of first two consecutive frames and the right eye image is then outputted over each of next two consecutive frames, approximate image data is inputted in every two consecutive frames. At this time, in the case of making a pair of two frames, image data inputted in the first frame may be temporarily stored and image data of the next frame based on the stored image may be outputted.